ROMK
Encyclopedia
ROMK is an acronym for the Renal Outer Medullary Potassium channel. This is an ATP-dependent potassium channel
(Kir1.1) that transports potassium out of cells. It plays an important role in potassium recycling in the thick ascending limb (TAL) and potassium secretion
in the cortical collecting duct (CCD) of the nephron
. In humans, ROMK is encoded by the KCNJ1 (potassium inwardly-rectifying channel, subfamily J, member 1) gene
. Multiple transcript variants encoding different isoforms have been found for this gene.
s are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier
type potassium channel. It is activated by internal ATP
and probably plays an important role in potassium homeostasis. The encoded protein has a greater tendency to allow potassium to flow into a cell rather than out of a cell.
, which is characterized by salt wasting, hypokalemic alkalosis, hypercalciuria, and low blood pressure.
Potassium channel
In the field of cell biology, potassium channels are the most widely distributed type of ion channel and are found in virtually all living organisms. They form potassium-selective pores that span cell membranes...
(Kir1.1) that transports potassium out of cells. It plays an important role in potassium recycling in the thick ascending limb (TAL) and potassium secretion
Secretion
Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland. In contrast to excretion, the substance may have a certain function, rather than being a waste product...
in the cortical collecting duct (CCD) of the nephron
Nephron
The renal tubule is the portion of the nephron containing the tubular fluid filtered through the glomerulus. After passing through the renal tubule, the filtrate continues to the collecting duct system, which is not part of the nephron....
. In humans, ROMK is encoded by the KCNJ1 (potassium inwardly-rectifying channel, subfamily J, member 1) gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
. Multiple transcript variants encoding different isoforms have been found for this gene.
Function
Potassium channelPotassium channel
In the field of cell biology, potassium channels are the most widely distributed type of ion channel and are found in virtually all living organisms. They form potassium-selective pores that span cell membranes...
s are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier
Inward-rectifier potassium ion channel
Inwardly rectifying potassium channels are a specific subset of potassium selective ion channels. To date, seven subfamilies have been identified in various mammalian cell types...
type potassium channel. It is activated by internal ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
and probably plays an important role in potassium homeostasis. The encoded protein has a greater tendency to allow potassium to flow into a cell rather than out of a cell.
Clinical significance
Mutations in this gene have been associated with antenatal Bartter syndromeBartter syndrome
Bartter syndrome is a rare inherited defect in the thick ascending limb of the loop of Henle. It is characterized by low potassium levels , increased blood pH , and normal to low blood pressure. There are two types of Bartter syndrome: neonatal and classic...
, which is characterized by salt wasting, hypokalemic alkalosis, hypercalciuria, and low blood pressure.